There are numerous golf practice devices described in the patent literature and on sale commercially. One device described in U.S. Pat. No. 5,390,930 features a magnetically restored ball position. Thus prior art golf practice device includes a pivoting base fixed on a mat or a grass yard, and a golf ball secured on a linking arm having a sleeve pivotally mounted on a shaft vertically erected on the pivoting base. Two rotor magnets having opposite outer magnetic poles are diametrically secured on two opposite ends of the sleeve, and two stator magnets having opposite inner magnetic poles are respectively secured on two opposite ends of a hanging bracket fixed on a top portion of the shaft. A rotation gap is defined between the rotor magnets and the stator magnets. A mutual attraction is established between each rotor magnet and each stator magnet, whereby upon striking of the ball by a club for rotating the ball, the ball will be stopped at its starting position as automatically restored by the magnetic force acting between each stator magnet and each rotor magnet.
There are several drawbacks and problems associated with this device. First, the device uses a standard golf ball that is fixedly secured onto the linking arm. As such, the ball does not rotate about a ball axis, as would be the case with an actual putt or golf club swing. Further, standard golf balls are dense and heavy objects such that if the ball becomes detached it may cause damage or injury. In addition, the linking arm rotates in a plane parallel to the mat or grass yard which also deviates from actual play insofar as balls hit with an iron or wood would assume an angled loft. A further shortcoming is that while the device uses magnetic attraction to restore ball position, it also uses magnetic repulsion, relying upon four magnets which increases complexity and manufacturing costs. The device is also secured to a mat or yard, decreasing flexibility and versatility.
Other, similar type devices on the market also use real golf balls which are inherently dangerous and prohibitive for indoor use. One such device is a vertical hanger design attached by a rope. It is notoriously difficult to adjust so that the ball rests on the hitting surface and breaks after minimal repeated use. The other device is an attachment to an expensive mat system that spins horizontally and has no stopping mechanism. Given the existing solutions, there remains an outstanding need for a less expensive, more versatile golf practice apparatus with a ball return function that more faithfully simulates ball flight dynamics experienced during actual play.